Thank you for your feedback!
I 100% agree on the flying enemies, one of the things I wanted to add was flying enemies, it was to make spikes more independent and less powerful, and give a threat that walls can't protect from, but that required new traps to be added as well which I couldn't do in time. Maybe in the future though, who knows? ;)
Dynamic music sounds like a great idea! I'll definitely add it to the list!